Water is becoming increasingly precious worldwide. Twenty-five nations are now experiencing chronic water shortages, and that number will certainly increase as we move into the 21st Century. Further, because world agriculture must be able to provide food for more than 11 billion people by the year 2050, pressure on water resources will increase further as the global community attempts to triple its agriculture output while simultaneously reducing environmental concerns.
Water that is applied to plants is largely lost as run off, evaporation and/or transpiration. Unfortunately, because of the plant's inefficient systems of regulating water loss through transpiration, farmers are forced to apply large quantities of water to compensate for the water that is lost by the plants. The amount of water used by the plants for growth is considerably less than the amount that the plant takes up and eventually loses. The majority of the water that is lost by the plants is lost through the stomata or pores on the surfaces of the leaves.
There are two basic methods of reducing water loss through the stomata. First, water loss may be reduced by physically plugging up the stomatal openings with a surface applied large organic polymer. A number of compounds that reduce water loss by physically coating the surfaces have been tested, and some of these compounds, e.g., latex emulsions, are effective. However, the effects are specific to the plant and environmental conditions, and the effectiveness of these types of anti-transpirant depends on complete coverage of the plant surfaces by water molecules. Further, the application is messy and not practical.
Alternatively, water loss may be reduced by introducing compounds into the plant and causing the stomata to close physiologically. Compounds such as abscisic acid and high carbon dioxide are capable of closing stomata. However the effects have been quite temporary and/or inconsistent. It is difficult to manage effectively these compounds without detrimental effects to plant quality.
A need therefore exists for a plant water loss reducing agent which is non-toxic to the plants, environmentally acceptable and relatively inexpensive. The present invention addresses this need by providing methods and compounds for reduction of plant water loss and for conditioning plants for water stress avoidance.